The invention relates generally to electro-optical methods and systems. More particularly, the invention relates to methods and systems directed to non-invasive monitoring of biologic tissues and motion thereof.
Despite the fact that approximately 1.7 million people are affected each year by traumatic brain injury (TBI), TBI remains an inadequately understood medical problem. The majority of TBI cases, some 80-90%, are characterized as mild TBI (mTBI), or concussions, and often result in few symptoms or sequelae, with many related to sports and recreation. The detailed pathophysiological mechanisms underlying TBI are complex, and many aspects of the injury process remain obscure. However, it is clear that there is an initial mechanical shock which can induce cellular compression and rending. Subsequent (secondary) brain damage can then result from: {1) insufficient oxygen supply (ischemia, hypoxia), (2) blood in contact with neurons or glia (hemorrhage), (3) inflammatory responses, (4) excitotoxic responses (post-injury glutamate release), (5) cytotoxic edema and, (6) hemodynamic dysregulation. All of these secondary insults evolve over periods ranging from minutes to hours to months or longer. The clinical course following TBI can also include the sudden and unpredictable appearance of edema or hemorrhage. Management of acute and subacute TBI focuses on identifying and preventing secondary sequelae, given that they are often preventable and associated with poor outcome.
One key variable in mTBI diagnosis and prognosis is knowing the nature and extent of the impact to the head. However, a notable technological gap exists in the ability to non-invasively monitor the movement of the brain during head motion in vivo, including mechanical shock that induces the TBI. Commercial devices implementing accelerometry measurements have traditionally been used to help quantify hits to the head in sports like football or hockey or cycling. However, such information may only be used to infer how the brain moves inside the skull during sudden acceleration or deceleration of the head. Other approaches have generally been limited to animal models with invasive sensors, which inherently change the nature of the cranial cavity and hence can affect the measurement of brain motion or injury itself.
Consequently, considering such limitations of previous technological approaches, it would be desirable to have a system and method for non-invasively detecting and enhancing brain measurements resulting from acute injuries or medical conditions.